This invention relates generally to a submarine cable and, more particularly, to an improved central strength member for such a cable.
A submarine cable basically consists of a central strength member with a surrounding inner conductor, in turn surrounded by plastic insulating material, in turn surrounded by an outer return conductor, the whole being sheated in a water impervious plastic sheath. This may be armoured with wire armouring for shallow water applications.
Generally, the central strength member comprises high tensile steel wires and the inner conductor comprises a copper tube embracing the wires. Similarly, the return conductor is normally a copper tube. In the inner conductor, the conductivity of the central strength members can be ignored to a large extent since their resistivity is high compared with that of copper.
It is an object of the present invention to modify the central strength member so as to decrease its weight and increase its conductivity and, thus, reduce the amount of copper required for the inner conductor.